下面哪个单位是发光强度的单位？（） ["A、流明","B、坎德拉","C、勒克斯","D、熙提"]
下面哪个单位是照度的单位？（） ["A、流明","B、坎德拉","C、勒克斯","D、熙提"]
关于胶片的叙述，错误的是 ["A．晶体颗粒大，感光度高","B．晶体颗粒分布均匀，对比度高","C．晶体颗粒大小不一，宽容度高","D．晶体颗粒小，分辨率低","E．晶体颗粒小，涂层薄，清晰度好"]
外耳孔与同侧眼眶下缘的连线称为 ["A．听眦线","B．听眶线","C．听鼻线","D．听口线","E．瞳间线"]
波浪的折射
河流的比降
